I would install the system on a single drive first, and add the 2 extra drives later.
That way you have more control.
/boot takes up approx 20Meg or something small like that, swap probably no more than 300Meg, (very much depending on your memory etc), so it seems a waste to assign a whole disk to each.
I would put .../files on a seperate disk and /ibays on another one.
Search the forums, there are some stories how to do this..
good luck..